Tanks for inductive apparatus



May 2, 1967 BUTTRlCK ET AL 3,317,080

TANKS FOR INDUCTIVE APPARATUS Filed Feb. 20, 1964 g 00 oo 00 i Z i OO--- 3---+ O 0o 3 F/GZ.

lnvenlors Attorneys United States Patent 3. 6 Claims. Cl. 220-71 This invention relates to tanks for inductive apparatus.

In operation inductive apparatus contained within a tank may generate noise which is transmitted to the tank. In an oil filled transformer, for example, noise is generated by vibration of the core and is transmitted through the oil and the core supports to the walls of the tank. The amplitude of the noise radiated by the tank depends on its mass and stiffness and it is sometimes desirable to reduce the stiffness of the tank walls in order to alter the ratio of mass to stiffness and thereby reduce the amplitude of the noise radiated. Previously, it has not been possible to reduce the stiffness to the desired extent since a minimum stiffness is required to prevent distortion of the tank walls beyond permissible limits, for example during vacuum processing or during testing of the apparatus under vacuum or pressure.

It is an object of the present invention to provide a tank for inductive apparatus in which the walls of the tank may have a lower stiffness than the walls of previously known tanks used under similar conditions.

According to the present invention at least one wall of a tank for inductive apparatus is provided with one or more stiifeners each comprising a rigid beam loosely secured at intervals along its length to said wall, said beam being spaced from said wall such that said wall is free to vibrate but distortion of said wall is limited by said beam.

Preferably, said beam is spaced from said wall by one or more resilient spacers.

The present invention will now be described by way of example with reference to the accompanying drawings in which:

FIGURE 1 is an elevation of a transformer tank provided with stiifeners in accordance with the invention, and

FIGURE 2 is an enlarged section of one wall of the tank shown in FIGURE 1.

Referring now to the drawings the transformer tank is provided on each wall 1 with stiffeners each of which comprises a T-sectioned beam 2 loosely secured at intervals along its length to the wall 1 by bolts 3 which pass freely through the beam 2. A resilient layer 4 is interposed between the beam 2 and the wall 1 and steel pads 5 are provided at the ends of the beam 2 which is supported such that there is a small gap between the pads 5 and the wall 1.

The core and windings of the transformer are mounted in the tank in the usual manner and when the transformer is energised the noise vibrations transmitted to the tank cause the walls 1 to vibrate, the amplitude of the vibrations being of the order of a thousandth of an inch. These vibrations 'are not transmitted to the beams 2 which therefore add mass to the walls 1 without affecting their stiffness with regard to the noise vibrations. When the tank is evacuated, however, as when vacuum processing the transformer during manufacture, each wall is distorted until the pads 5 engage the wall and further dis tortion is then resisted by the beams 2 which have sufiicient rigidity to limit the distortion to a safe value. Since the distortion of the walls is limited in this manner their stiffness may be reduced to the desired extent.

The beams 2 need not necessarily be T-sectioned as described above, and although the bolts 3 have been 3,317,080 Patented May 2, 1967 shown as being threaded directly into the walls 1, suitable pads may be welded to the walls to receive the bolts if the walls do not have sufiicient thickness. Also, the steel pads 5 may be welded to the wall 1 instead of the beam 2 such that there is a small gap between the pads 5 and the beam 2, and further pads may be provided along the length of the beam 2 such that the stiffeners will also resist distortion due to internal pressure. Furthermore, although the tank in FIGURE 1 has been shown as having only vertical stiifeners, horizontal or angular stiffeners may be provided in addition to or instead of the vertical stiffeners shown. Furthermore, if required, the stiffeners may be continuous around the corners of the tank.

What we claim is:

1. A tank for inductive apparatus, at least one wall of said tank being provided with one or more stiifeners, said stiffeners each comprising a rigid beam member more rigid than said wall and loosely secured at intervals along its length to said wall, said beam member being spaced from said wall such that said wall is free to vibrate, but distortion of said wall is limited by said beam member, and metallic pads disposedbetween said wall and each said beam member, said metallic pads being secured to one of said wall or said beam member such that said pads are spaced from the other of said wall or said beam member by a small gap.

2. A tank for inductive apparatus as claimed in claim 1 in which said pads are secured to said wall adjacent each said beam, said pads being spaced from each said beam by a small gap.

3. A tank for inductive apparatus as claimed in claim 1 in which said pads are secured to each said beam, said pads being spaced from said wall by a small gap.

4. A tank for inductive apparatus, at least one wall of said tank being provided with one or more stiffeners each comprising a rigid beam loosely secured at intervals along its length to said wall, said beam(s) being spaced from said wall by resilient spacing means such that said wall is free to vibrate but distortion of said wall is limited by said beam(s) and metallic pads secured to each said beam, said pads being spaced from said wall by a small gap.

5. A tank for inductive apparatus as claimed in claim 4 in which said pads are secured at the two ends of each said beam.

6. A tank for inductive apparatus, at least one wall of said tank being provided with one or more stiifeners, said stiifeners each comprising a rigid beam member more rigid than said wall and loosely secured at intervals along the length of saidwall, said beam member being spaced from said wall such that said wall is free to vibrate, but distortion of said wall is limited by said beam member, a layer of resilient material interposed between said beam member and said wall member and extending along substantially the full length of said beam member, and metallic pads secured between said wall and each beam member adjacent opposite ends of said resilient layer, said pads being spaced from either said wall or said beam member by a small gap.

"Ice

References Cited by the Examiner UNITED STATES PATENTS 698,497 4/ 1902. Hill 22071 1,359,057 11/1920 Guldaman 22071 1,427,525 8/ 1922 Felten 220-12 2,170,525 8/1939 Ball 22071 2,173,804 9/1939 Hanrahan 220-71 THER-ON E. CONDON, Primary Examiner.

JAMES R. GARRET, Examiner. 

1. A TANK FOR INDUCTIVE APPARATUS, AT LEAST ONE WALL OF SAID TANK BEING PROVIDED WITH ONE OR MORE STIFFENERS, SAID STIFFENERS EACH COMPRISING A RIGID BEAM MEMBER MORE RIGID THAN SAID WALL AND LOOSELY SECURED AT INTERVALS ALONG ITS LENGTH TO SAID WALL, SAID BEAM MEMBER BEING SPACED FROM SAID WALL SUCH THAT SAID WALL IS FREE TO VIBRATE, BUT DISTORTION OF SAID WALL IS LIMITED BY SAID BEAM MEMBER, AND METALLIC PADS DISPOSED BETWEEN SAID WALL AND EACH SAID BEAM MEMBER, SAID METALLIC PADS BEING SECURED TO ONE OF SAID WALL OR SAID BEAM MEMBER SUCH THAT SAID PADS ARE SPACED FROM THE OTHER OF SAID WALL OR SAID BEAM MEMBER BY A SMALL GAP. 